This invention is generally in the field of medical devices, and more particularly in the field of drug delivery devices.
Drug delivery involves delivering a drug or other therapeutic compound into the body. Typically, the drug is delivered via a technology that is carefully selected based on a number of factors. These factors include but are not limited to the characteristics of the drug, such as drug dose, pharmacokinetics, complexity, cost, and absorption, the characteristics of the desired drug delivery profile (such as uniform, non-uniform, or patient-controlled), the characteristics of the administration mode (such as the ease, cost, complexity, and effectiveness of the administration mode for the patient, physician, nurse, or other caregiver), or other factors or combinations of these factors.
Conventional drug delivery technologies present various challenges. Oral administration of a dosage form is a relatively simple delivery mode, but some drugs may not achieve the desired bioavailability and/or may cause undesirable side effects if administered orally. Further, the delay from time of administration to time of efficacy associated with oral delivery may be undesirable depending on the therapeutic need. While parenteral administration by injection may avoid some of the problems associated with oral administration, such as providing relatively quick delivery of the drug to the desired location, conventional injections may be inconvenient, difficult to self-administer, and painful or unpleasant for the patient. Furthermore, injection may not be suitable for achieving certain delivery/release profiles, particularly over a sustained period of time.
Passive transdermal technology, such as a conventional transdermal patch, may be relatively convenient for the user and may permit relatively uniform drug release over time. However, some drugs, such as highly charged or polar drugs, peptides, proteins and other large molecule active agents, may not penetrate the stratum corneum for effective delivery. Furthermore, a relatively long start-up time may be required before the drug takes effect. Thereafter, the drug release may be relatively continuous, which may be undesirable in some cases. Also, a substantial portion of the drug payload may be undeliverable and may remain in the patch once the patch is removed.
Active transdermal systems, including iontophoresis, sonophoresis, and poration technology, may be expensive and may yield unpredictable results. Only some drug formulations, such as aqueous stable compounds, are suited for active transdermal delivery. Further, modulating or controlling the delivery of drugs using such systems may not be possible without using complex systems.
Infusion pump systems may be large and may require tubing between the pump and the infusion set, impacting quality of life. Further, infusion pumps may be expensive and may not be disposable. From the above, it would be desirable to provide new and improved drug delivery systems and methods that overcome some or all of these and other drawbacks.